Generally, an air conditioner is an apparatus which adjusts temperatures and humidity of indoor air using a refrigeration cycle and may cool a room by suctioning and heat-exchanging warm air with a low-temperature refrigerant and discharging the cooled air into the room, or on the other hand, may heat a room by suctioning and heat-exchanging an inside low-temperature air with a high-temperature refrigerant and discharging the heated air.
An air condition may include an outdoor unit installed in an outdoor space and an indoor unit installed in an indoor space. The outdoor unit may include a compressor for compressing a refrigerant, an outdoor heat exchanger for heat-exchanging outdoor air with a refrigerant, an air blowing fan, and a variety of pipes which connects the compressor to the indoor unit. The indoor unit may include an indoor heat exchanger for heat-exchanging indoor air with a refrigerant and an expansion device.
The air conditioner may cool or heat the room through a refrigerant cycle which circulates the compressor, the indoor heat exchanger (condenser), the expansion device, and the indoor heat exchanger (evaporator) in forward or reverse directions.
In detailed consideration of the refrigerant cycle, a gas refrigerant compressed by the compressor flows into the outdoor heat exchanger and phase-changes into a liquid refrigerant, heat is released outward while the refrigerant phase-changes at the outdoor heat exchanger, and then the refrigerant discharged from the outdoor heat exchanger expands while passing through the expansion device and flows into the indoor heat exchanger.
Afterward, the liquid refrigerant which flows into the indoor heat exchanger phase-changes into a gas refrigerant. Likewise, the refrigerant phase-changes at the indoor heat exchanger and absorbs outside heat.
As described above, the air conditioner adjust an indoor temperature by discharging air (cold air) heat-exchanged by characteristics in which ambient heat is absorbed when a liquid state refrigerant evaporates or the heat is discharged when a gas state refrigerant is liquefied.
Meanwhile, in a space in which a lot of large-sized servers and electronic equipment are installed, cooling is performed even in winter to stably operate the servers and electronic equipment. Particularly, when an outdoor temperature is low, a condensing temperature of a refrigerant which passes through an outdoor heat exchanger decreases and an evaporating temperature of a refrigerant which passes through an indoor heat exchanger decreases.
Also, a phenomenon in which a liquid refrigerant that flows into a compressor or an indoor heat exchanger freezes occurs and causes unstable operation of an air conditioner and an increase in power consumption from over-operating the compressor.